In general, a currently popular electronic-ink display panel comprises: a front plane laminate (FPL), an electronic-ink layer and a thin film transistor (TFT) array substrate, wherein the front plane laminate has a transparent electrode, and the electronic-ink layer has display material which is operated by charged particles and has bi-stable states.
Using a conventional electronic-ink layer as an example, the charged particles includes positively charged particles and negatively charged particles contained in respective microcapsules with a transparent fluid, wherein the color of the positively charged particles and that of the negatively charged particles are different, such as black and white. When the electric fields between the pixel electrodes and the transparent electrode on the TFT array substrate are varied, the positively charged particles and negatively charged particles of different colors will be moved upwards or downwards in accordance with the direction of the electric fields, thereby enabling the respective microcapsules to show white or black color. Further, each of the microcapsules may contain single-polarity charged particles and an opaque fluid, wherein the color of the single-polarity charged particles and that of the opaque fluid are different, such as black and white. When the electric fields between the pixel electrodes and the transparent electrode are varied, the single-polarity charged particles will be moved upwards or downwards in accordance with the direction of the electric fields, thereby enabling the microcapsules to show white or black color.
Using another conventional electronic-ink layer as an example, each of the charged particles is a bi-color charged particle, which shows two different colors on its respective surfaces. The surfaces of the bi-color charged particle own different polarities of charges in accordance with their colors. When the electric fields between each of the pixel electrodes and the transparent electrode on the TFT array substrate are varied, the bi-color charged particles will roll in accordance with the direction of the electric fields, thereby enabling the respective charged particles to show white or black color.
FIG. 1A is a schematic diagram showing the structure of a conventional electronic-ink display panel. FIG. 1B is a schematic top view showing a TFT array substrate of the electronic-ink display panel illustrated in FIG. 1A, wherein FIG. 1A is a cross-sectional view showing the thin film transistor array substrate of the electronic-ink display panel viewed along the A-A′ line in FIG. 1B. Referring to FIG. 1A and FIG. 1B simultaneously, an electronic-ink display panel 10 comprises a TFT array substrate 20, a front plane laminate 30, and an electronic-ink layer 40, wherein the front plane laminate 30 is disposed above the TFT array substrate 20. The electronic-ink layer 40 is disposed between the front plane laminate 30 and the TFT array substrate 20.
The TFT array substrate 20 comprises a substrate 21, a plurality of scan lines 22, and a plurality of sub-pixel units 24, wherein the scan lines 22 and data lines 23 are disposed on the substrate 21 to define a plurality of pixel areas 21a thereon. The sub-pixel units 24 are respectively disposed in the pixel areas 21a on the substrate 21, and each of the sub-pixel units 24 has a storage capacitor 24a. In addition, each of the sub-pixel units 24 has a thin film transistor 24b and a pixel electrode 24c. The thin film transistor 24b is electrically connected to one of the scan lines 22 and one of the data lines 23. The pixel electrode 24c is electrically connected to the thin film transistor 24b. The front plane laminate 30 comprises a protection film 32 and a transparent electrode layer 34, wherein the protection film 32 is disposed on the transparent electrode 34.
In accordance with the above description, the pixel electrode 24c can be charged or discharged by applying proper voltage signals to the scan lines 22, data lines 23 and the transparent electrode 34. Thus, the charged particles contained in the microcapsule 41 in the electronic-ink layer 40 are driven for enabling the electronic-ink display panel 10 to display images. However, the aforementioned electronic-ink display panel 10 can merely show a black-and-white display, and thus the applications of the electronic-ink display panel 10 are limited.
FIG. 1C is a schematic diagram showing the structure of another conventional electronic-ink display panel 42. The electronic-ink display panel 42 is similar to the electronic-ink display panel 10 shown in FIG. 1A, but is different in that the electronic-ink layer 40 of the electronic-ink display panel 42 uses bi-color charged particles 44 to replace the microcapsules 41 shown in FIG. 1A.
FIG. 1D is a schematic diagram showing the structure of further another conventional electronic-ink display panel 45. The electronic-ink display panel 45 is similar to the electronic-ink display panel 10 shown in FIG. 1A, but is different in that the microcapsule 41 in the electronic-ink layer 40 of the electronic-ink display panel 45 comprises an opaque fluid 46 (for example in white color) and single-polarity charged particles 47 (for example in black color). The single-polarity charged particles 47 move upwards or downwards in accordance with the direction of the electric field applied thereto. If the single-polarity charged particles 47 move upwards, the electronic-ink display panel 45 shows black color. If the single electricity particles move downwards, the electronic-ink display panel 45 shows white color.